High rates of heart disease lower the life expectancy of people with mental illness about 25 to 30 years, a psychiatrist from Washington University said.

Dr. John W. Newcomer said that a variety of factors influence the health and mortality rates of people with problems such as schizophrenia, bipolar disorder and major depression.

One factor is that people with major mental disorders have a harder time learning and working, which leads to lower income and less access to medical care.

He also said that 50 percent to 80 percent of these patients smoke.

Further, their psychiatric medications can contribute to weight gain and a lack of activity.

"All of this adds up," Newcomer said. "They are more likely to eat more high-fat food and to burn fewer calories, so it's not surprising that this population also tends to have higher rates of overweight and obesity."

Newcomer said data from a national study of 1,500 patients with chronic schizophrenia found that 88 percent of patients entering the study with high cholesterol did not take lipid-lowering drugs. Another 30 percent with diabetes at the start of the study received no anti-diabetes medications, and 62 percent of those with high blood pressure were not taking any antihypertensive medication.

He said the solution is for psychiatrists and other health providers to work together to make sure the mentally ill are properly screened and monitored.